| cross-protective immunity induced by babesia bovis clones with antigenically unrelated variable merozoite surface antigens. | babesia bovis merozoite surface antigen 1 (msa-1) induces antibodies capable of neutralizing merozoites in vitro. both msa-1 and the co-expressed msa-2 are encoded by a polymorphic multigene family and are antigenically variant among strains isolated from widely separated geographic regions. in this study, cross-protective immunity between two b. bovis clones, mexico mo-7 and israel-c, that have antigenically unrelated msa-1 and msa-2 surface proteins was assessed. cattle immunized by infection ... | 1994 | 7941314 |
| antigenic profile of a pure isolate of anaplasma marginale of brazilian origin, using a western blot technique. | anaplasma marginale initial bodies of the brazilian isolate aufv1 were purified from infected erythrocytes using a combination of lysis, ultrasonic disruption and differential centrifugation. initial bodies were solubilised with a buffer containing protease inhibitors and non-ionic detergents. immunochemical analysis by the western blot technique revealed at least five proteins with apparent molecular weights (mw) of 105, 100, 97, 87 and 38 kda when homologous sera were used as primary antibodie ... | 1994 | 8030178 |
| babesia bovis: infectivity of an attenuated strain of brazilian origin for the tick vector, boophilus microplus. | in order to verify the infectivity and transovarian transmission of one strain of babesia bovis of brazilian origin, attenuated by repeated passages in splenectomized calves to the biological tick vector, boophilus microplus, an inoculation of that strain was performed in hemoparasite-free calves infested with hemoparasite-free ticks. subsequently, engorged female ticks were collected to examine hemolymph and progeny for presence of developing stages of babesia bovis. using an optical microscope ... | 1994 | 8030179 |
| bovine anaplasmosis and babesiosis in the lesser antilles: risk assessment of an unstable epidemiologic situation. | a seroepidemiological survey on tick-borne diseases of ruminants was carried out on 11 islands of the lesser antilles from grenada to st martin. a total of 1,795 cattle were randomly sampled and sera tested for antibodies to anaplasmosis (anaplasma marginale) and babesiosis (babesia bovis and b bigemina) using a dot-elisa test. except for anaplasmosis, which was virtually absent from guadeloupe, the seroprevalence of the 3 tick-borne diseases ranged from 18 to 71%. the epidemiologic situation wa ... | 1994 | 8038806 |
| adenosine analogues as antimetabolites against plasmodium falciparum malaria. | analogues of purine nucleosides and deoxynucleosides were tested for toxicity against the intraerythrocytic parasite plasmodium falciparum in vitro culture. sangivamycin (7-deaza-7-amido-adenosine) (ic37 of 0.3 microm), tubercidin (7-deaza-adenosine) (ic37 of 0.7 microm), 6-methylamino-deoxyadenosine (ic37 of 10 microm), 8-aza-2-amino-deoxy-adenosine (ic37 of 11 microm) and 2-chloro-adenosine (ic37 of 11 microm) were found to be the most toxic towards the parasite. structure-activity analysis su ... | 1994 | 8070953 |
| use of random amplified polymorphic dna analysis to compare babesia bovis and b. bigemina isolates. | random amplified polymorphic dna analysis provides characteristic fingerprints for babesia bovis and b. bigemina. this genetic profile reflects similarities and minor differences between closely related regional isolates and the greater diversity representative of species from distant geographic locations. | 1994 | 8073018 |
| use of in vitro culture to isolate babesia bovis from theileria buffeli, eperythrozoon wenyoni and anaplasma spp. | on nine separate occasions, babesia bovis microaerophilus stationary phase (masp) cultures were initiated with blood from calves with concurrent infections of b. bovis and theileria buffeli, eperythrozoon wenyoni or anaplasma spp. in each case b. bovis became established in culture and was maintained for 30-49 days. culture material was inoculated into susceptible splenectomised calves to test for persistence of the other organisms. no haemoparasites other than b. bovis were detected in giemsa-s ... | 1994 | 8091617 |
| molecular variation and diversity in candidate vaccine antigens from babesia. | recombinant vaccines are being developed against a number of species of protozoan parasites in the genus babesia. protozoan parasites are notorious for their diversity of strains and their ability to express families of equivalent, but antigenically distinct, surface proteins. in order to reduce the likelihood of evasion of the immune response induced by a recombinant vaccine, ideal components should be essential proteins encoded by single copy genes. the proteins should also have a limited abil ... | 1993 | 8100672 |
| evaluation of the infectivity of a vaccinal and a pathogenic babesia bovis strain from argentina to boophilus microplus. | three trials were performed to test the infectivity of a vaccinal and a pathogenic strain of babesia bovis for the tick boophilus microplus. the progeny of engorged female ticks fed on calves inoculated with the pathogenic strain were able to transmit the infection to splenectomised calves (measured by the presence of the parasite in their blood and seroconversion), whereas the progeny of engorged females fed on calves inoculated with the vaccinal strain did not transmit the organisms. these res ... | 1993 | 8128578 |
| toxicology of a bovine paraplegic syndrome. | a clinical entity named 'bovine paraplegic syndrome' ('síndrome parapléjico de los bovinos') has spread alarmingly in the cattle-growing areas of the central and eastern plains of venezuela. it is estimated that four million cattle are bred in the area where the disease occurs. the mortality ranges from 5 to 25% of the animals at risk, mostly pregnant or lactating cows. the principal characteristic of the bovine paraplegic syndrome is ventral or sternal decubitus, in animals that make vain effor ... | 1993 | 8146871 |
| a study of autoantibodies to phosphatidyl-serine in babesia bovis and babesia bigemina infections in cattle. | sera from cattle infected with babesia bovis were found to contain antibodies to phosphatidyl-serine (ps), a negatively charged phospholipid normally found on the internal membrane of erythrocytes. in contrast, no autoantibodies were detected following babesia bigemina infection indicating that the autoimmunity is not genus specific. during infection with babesia bovis, ps translocates to the external membrane and it is suggested that this may result in ps behaving as an autoantigen owing to a t ... | 1994 | 8160363 |
| babesia bigemina: isolation and characterization of merozoite rhoptries. | babesia bigemina apical membrane polypeptide p58, encoded by a multigene family with homologues in other babesia spp. and sequence similarity to rhoptry proteins in other apicomplexan parasites, was identified within merozoite rhoptries using immunoelectron microscopy. to identify additional b. bigemina rhoptry proteins, rhoptries were isolated from french pressure cell-disrupted merozoites fractionated by differential centrifugation and isopycnic sucrose density gradient centrifugation. a fract ... | 1993 | 8224087 |
| antigenic variation of parasite-derived antigens on the surface of babesia bovis-infected erythrocytes. | the hemoparasite babesia bovis antigenically alters the bovine erythrocyte membrane surface by expression of isolate-specific, parasite-derived polypeptides. to determine whether antigenic variation also occurred on the infected erythrocyte surface, a calf was infected once with parasitized erythrocytes carrying the c9.1 clonal line of b. bovis. in vitro cultures then were established periodically from the peripheral blood and analyzed with sequentially collected sera from the same animal. the s ... | 1994 | 8262654 |
| multiplex polymerase chain reaction based assay for the detection of babesia bigemina, babesia bovis and anaplasma marginale dna in bovine blood. | a highly sensitive polymerase chain reaction (pcr) based method was developed to detect, in the same blood sample, dna of hemoparasites frequently found together infecting cattle in tropical and subtropical areas. bovine blood containing equal parasitemias of babesia bigemina, b. bovis and anaplasma marginale infected erythrocytes was mixed to standardize the test. twenty microliters of 10-fold dilutions from the pooled blood sample were resuspended in pcr mixture buffer containing each of the s ... | 1993 | 8291198 |
| isolation, initial characterization and serological studies of glycolipid antigens from babesia bovis-infected erythrocytes. | serological analysis of babesia bovis-derived glycolipids by elisa and the indirect fluorescent antibody technique demonstrated the existence of their antigenic and immunogenic activities not only in b. bovis but also in b. bigemina infections. this indicates that serological cross-reactivity of b. bovis and b. bigemina relates to glycolipids. the negative elisa reaction obtained with anaplasma marginale antisera suggested the specificity of the reaction to the genus babesia. fractionation of th ... | 1993 | 8300296 |
| heterogeneity in cytokine profiles of babesia bovis-specific bovine cd4+ t cells clones activated in vitro. | the central role of t cells in the immune response against hemoprotozoan parasites, both as helper cells for t cell-dependent antibody production and as effector cells acting on intracellular parasites through the elaboration of cytokines, has prompted an investigation of the bovine cellular immune response against babesia bovis antigens. cd4+ t helper (th) cell clones generated from four b. bovis-immune cattle by in vitro stimulation with a soluble or membrane-associated merozoite antigen were ... | 1993 | 8335361 |
| cloning and characterisation of cdna clones encoding two babesia bovis proteins with homologous amino- and carboxy-terminal domains. | a dextran sulphate protein (dsp) fraction derived from babesia bovis has previously been shown to induce a protective immune response in cattle. a b. bovis cdna library was screened with both the complete anti-dsp serum and a subfraction of the anti-dsp serum affinity purified on a native b. bovis protein of approx. 80 kda. cdna clones encoding two different b. bovis proteins were identified. the product of one gene, bv80, has a single divergent copy of a sequence of 149 amino acids (approx. 30% ... | 1993 | 8341317 |
| sequence of a cdna encoding beta-tubulin from babesia bovis. | | 1993 | 8341332 |
| babesia bovis: characterization of the t helper cell response against the 42-kda merozoite surface antigen (msa-1) in cattle. | the babesia bovis major merozoite surface antigen (msa-1) is a 42-kda integral membrane glycoprotein previously shown to induce immunodominant antibody responses in cattle protectively immune to b. bovis and to induce neutralizing antibody. recent studies have also shown that msa-1 b cell epitopes common to new world strains of b. bovis are not present in either israel or australia strains. to understand the potential role of this protein in protective immunity, t helper cell responses specific ... | 1993 | 8344411 |
| the toxicity of antifolates in babesia bovis. | a variety of anti-folate compounds have been tested for their ability to inhibit the growth of babesia bovis as measured by the incorporation of [3h]hypoxanthine into the parasite's nucleic acids. inhibitors of folate synthesis (including 7-methylguanosine and several sulpha drugs) were without effect but several structural analogues of folate were toxic. the most potent folate analogues were the lipophilic compounds piritrexim and trimetrexate, each causing 50% inhibition of [3h]hypoxanthine in ... | 1993 | 8359989 |
| isolate-specific parasite antigens of the babesia bovis-infected erythrocyte surface. | bovine erythrocytes taken from in vitro cultures of babesia bovis parasites from mexico and the united states were assayed for the presence of new epitopes on the erythrocyte surface. new surface-exposed epitopes were detected by means of a whole-cell antigen capture assay. these epitopes were subsequently demonstrated only on infected erythrocytes by immunofluorescence staining of intact, living cells. parasite-synthesized antigens were identified on each isolate using a surface-specific immuno ... | 1993 | 8366886 |
| steroid hormone dependent changes in dna methylation and its significance for the activation or silencing of specific genes. | | 1993 | 8380354 |
| characterisation of a family of multi-copy genes encoding rhoptry protein homologues in babesia bovis, babesia ovis and babesia canis. | a monoclonal antibody that had been raised against a protease-containing fraction of babesia bovis, and shown to bind to a protein located in the rhoptries, was used to screen a b. bovis cdna expression library. the sequence of the protein encoded by a positive clone was almost identical to the equivalent region of a previously described b. bovis 60-kda rhoptry protein (bv60). a tandem repeat of the gene encoding bv60 was identified in all australian isolates of b. bovis examined. genes encoding ... | 1993 | 8433711 |
| in vitro growth of babesia bovis in white-tailed deer (odocoileus virginianus) erythrocytes. | babesia bovis cultured in bovine erythrocytes was passaged into white-tailed deer (odocoileus virginianus) erythrocytes and medium containing either white-tailed deer serum or bovine serum. deer erythrocytes supported the growth of the parasite only in the presence of bovine serum. cryopreserved cultures were recovered successfully in white-tailed deer erythrocytes. by light and electron microscopy, b. bovis structure appeared similar in host cells of either species. | 1993 | 8459334 |
| a nonsubjective assay for antigenic modifications of the babesia bovis-parasitized erythrocyte surface. | intracellular protozoan parasites induce numerous alterations in the invaded host cell, including antigenic modifications of the host cell plasma membrane. we have developed a quantifiable, non-subjective assay for the detection of novel antigenic reactivities on the host cell surface using as a model system bovine erythrocytes infected with babesia bovis. infected erythrocytes, metabolically labeled with l-[35s]methionine, were sensitized by incubation with bovine immune serum, then were captur ... | 1993 | 8459338 |
| identification of a babesia bovis gene with homology to the small subunit ribosomal rna gene from the 35-kilobase circular dna of plasmodium falciparum. | isolation of a 552-base pair (bp) fragment of a putative extrachromosomal small subunit ribosomal rna (ssrrna) gene from babesia bovis was achieved using the polymerase chain reaction (pcr) followed by cloning and sequencing of the pcr product. the sequences of the oligonucleotide primers used for the pcr were derived from selected known sequences in the organellar ssrrna gene which is encoded within the 35-kilobase (kb) circular dna from plasmodium falciparum. comparison of the sequence of the ... | 1993 | 8468131 |
| efficacy of an australian babesia bovis vaccine strain in malawi. | three calves vaccinated with the australian ka strain of babesia bovis were fully protected against experimental infection with an isolate from a farm on which four of 210 vaccinated cattle had died from b bovis infection. a degree of cross protection against the isolate was demonstrated in one calf which had been infected previously with babesia bigemina. | 1993 | 8470344 |
| analysis of dinucleotide frequency and codon usage in the phylum apicomplexa. | dinucleotide frequency (dif) and codon usage (cu) were analysed in gene sequences from four parasitic protozoa, babesia bovis, theileria parva, toxoplasma gondii and eimeria tenella, of the phylum apicomplexa. in keeping with the 'genome hypothesis', cu was found to be non-random and species specific in these organisms, although cu among members of the same subclass was found to be very similar. several low-usage (lu) codons were identified, and the usage of lu codons appears to be related to th ... | 1993 | 8482530 |
| babesia bovis: in vitro phagocytosis promoted by immune serum and by antibodies produced against protective antigens. | the in vitro phagocytosis of both babesia bovis-infected red cells and of parasites exposed by lysis of infected red blood cells is demonstrated in a phagocytic mouse model. twenty-four b. bovis immune sera were tested alone or as a pool as were antibodies (ds antibodies) raised against a b. bovis protective fraction, prepared by dextran sulfate precipitation. all the immune sera failed to promote significant levels of phagocytosis, whereas the other antibodies (ds antibodies) consistently induc ... | 1993 | 8493246 |
| phylogeny of the large extrachromosomal dna of organisms in the phylum apicomplexa. | organisms in the phylum apicomplexa appear to have a large extrachromosomal dna which is unrelated to the mitochondrial dna. based on the apparent gene content of the large (35 kb) extrachromosomal dna of plasmodium falciparum, it has been suggested that it is a plastid-like dna, which may be related to the plastid dna of rhodophytes. however, phylogenetic analyses have been inconclusive. it has been suggested that this is due to the unusually high a+t content of the plasmodium falciparum large ... | 1995 | 8520581 |
| exoantigens of an attenuated strain of babesia bovis used as a vaccine against bovine babesiosis. | bovine babesiosis caused by babesia bovis remains a significant constraint to beef and milk cattle production throughout the world. exoantigens released by the parasites in culture supernatants are a potential source of antigen to induce protective immunity. an attenuated strain of b. bovis from brazil, catalogued as bbufv1, was maintained in vitro by the masp method, and exoantigen-containing supernatant fluids were collected daily to form a pool representing a 72-h culture cycle for preparatio ... | 1995 | 8533277 |
| babesia bigemina: identification of b cell epitopes associated with parasitized erythrocytes. | rhoptries are involved in host cell invasion and rhoptry polypeptides, including the babesia bigemina rhoptry-associated protein-1 (rap-1), are targets for protective immune responses. polyclonal antisera produced against isolated rhoptries is directed predominantly against rap-1 and reacts with both the merozoite and the membrane of parasitized erythrocytes. to determine whether these b cell epitopes associated with the parasitized erythrocyte are derived from rap-1 or, alternatively, from prev ... | 1995 | 8542990 |
| an organelle-like small subunit ribosomal rna gene from babesia bovis: nucleotide sequence, secondary structure of the transcript and preliminary phylogenetic analysis. | investigations aimed at identifying the mitochondrial genome of babesia bovis using the polymerase chain reaction (pcr) have established the existence of an organelle-like small subunit ribosomal rna (ssu rrna) gene in the parasite. the sequence, compiled from three main pcr products, was 1448 bp in length (including the primer regions), had a 73% a+t content and showed significant similarity (68% sequence identity) to the "organellar" ssu rrna gene from plasmodium falciparum. the proposed secon ... | 1995 | 8550293 |
| interleukin-10 downregulates proliferation and expression of interleukin-2 receptor p55 chain and interferon-gamma, but not interleukin-2 or interleukin-4, by parasite-specific helper t cell clones obtained from cattle chronically infected with babesia bovis or fasciola hepatica. | human recombinant interleukin-10 (il-10) was previously shown to inhibit accessory cell (ac)-dependent proliferation of bovine parasite-specific t helper 1 (th1), th2, and th0 cells in an il-2-reversible manner (brown, w.c., woods, v.m., chitko-mckown, c.g., hash, s.m., and rice-ficht, a.c., 1994. infect. immun. 62, 4697-4708). the present study was therefore designed to determine whether the effect of il-10 on t cell proliferation corresponded with downregulated expression of cytokines, or thei ... | 1995 | 8564714 |
| detection of theileria annulata in blood samples of carrier cattle by pcr. | we report the detection of theileria annulata, the causative agent of tropical theileriosis, by pcr in blood samples obtained from carrier cattle. the assay employs primers specific for the gene encoding the 30-kda major merozoite surface antigen of t. annulata. a 721-bp fragment was amplified from blood samples taken monthly from calves experimentally infected with one of four different stocks of t. annulata originating in either mauritania, portugal, spain, or turkey. at the end of the experim ... | 1995 | 8567902 |
| detection of anaplasma marginale dna in bovine erythrocytes by slot-blot and in situ hybridization with a pcr-mediated digoxigenin-labeled dna probe. | a 409-base pair (bp) dna fragment derived from the msp-1 beta gene of anaplasma marginale was amplified and simultaneously labeled with digoxigenin-11-dutp by a polymerase chain reaction (pcr) assay. the resulting digoxigenin-labeled 409-bp pcr product was used as a probe for slot-blot and in situ hybridization to detect a. marginale dna from experimentally infected bovine erythrocytes. the hybrid formation was detected with alkaline phosphatase-conjugated anti-digoxigenin antibody and substrate ... | 1995 | 8580166 |
| non-histone protein 1 (nhp1) is a member of the ku protein family which is upregulated in differentiating mouse myoblasts and human promyelocytes. | we have previously purified and characterized a ubiquitous non-histone protein (nhp1) which has a high affinity (kd 10(-11) m) for different avian vitellogenin gene sequences containing cpgs (hughes et al. (1989) biochemistry 28, 9137-9142; hughes and jost (1989) nucleic acids res. 17, 8511-8520). here we show by microsequencing that the peptides derived from the purified p75 and p85 subunits of nhp1 from hela cells have between 64 and 100% identity with the human ku autoantigen. during the diff ... | 1996 | 8605992 |
| cloning and characterization of a ribosomal p protein from taenia solium, the aetiological agent of human cysticercosis. | a cdna encoding the complete open reading frame of the taenia solium acidic ribosomal phosphoprotein p2 has been cloned. the 417 bp cdna (arpp2) was isolated from a t. solium cdna expression library by pcr using p protein specific pimers. the orf encodes a protein of 121 amino acids exhibiting 40-55% identity to mammalian, fungal, insect, and parasite p2 proteins. the inferred molecular mass of the protein is 12,592 daltons, similar to that reported for other ribosomal p2 proteins. after subclon ... | 1996 | 8619813 |
| cd4+ t-helper lymphocyte responses against babesia bigemina rhoptry-associated protein i. | a multigene family of 58- to 60-kda proteins, which are designated rhoptry-associated protein 1 (rap-1) and which come from the parasites babesia bigemina and babesia bovis, is a target for vaccine development. the presence of multiple gene copies and conserved sequences and epitopes of rap-1 implies that these proteins are functionally important for the survival of these parasites. furthermore, it was previously shown that b. bigemina rap-1 induced partial protection against challenge infection ... | 1996 | 8675310 |
| a babesia bovis 225-kilodalton spherical-body protein: localization to the cytoplasmic face of infected erythrocytes after merozoite invasion. | a 225-kda babesia bovis protein occurs on the cytoplasmic side of infected-erythrocyte membranes. here it is demonstrated that the 225-kda protein localizes to spherical-body organelles of merozoites. organelles consistent in size and shape with spherical bodies were isolated between 1.17 and 1.21 g/cm(3) in a sucrose density gradient. organelles consistent with rhoptries and micronemes were also present in fractions from 1.17 to 1.19 g/cm(3). antisera generated by immunizing mice with the fract ... | 1996 | 8698487 |
| the structural gene for carbamoyl phosphate synthetase from the protozoan parasite babesia bovis. | | 1995 | 8719167 |
| babesia bovis rhoptry-associated protein 1 is immunodominant for t helper cells of immune cattle and contains t-cell epitopes conserved among geographically distant b. bovis strains. | the ability of rhoptry-associated protein 1 (rap-1) of babesia bovis and babesia bigemina to confer partial protective immunity in cattle has stimulated interest in characterizing both b-cell and t-cell epitopes of these proteins. it was previously shown that b. bovis rap-1 associates with the merozoite surface as well as rhoptries and expresses b-cell epitopes conserved among otherwise antigenically different b. bovis strains. an amino-terminal 307-amino-acid domain of the molecule that is high ... | 1996 | 8757873 |
| effect of management and inherent factors on birth seropositivity and seroconversion to babesia bovis in calves in costa rica. | the relationship between calf characteristics, farm management, seropositivity, and age at seroconversion to babesia bovis was assessed. a total of 3624 samples obtained from 494 animals on 11 farms was analyzed by an indirect elisa assay, and individual results classified as positive or negative. the animals were sampled from birth to weaning, beginning in april 1990 and ending in april 1992. we found 59.1% (n = 467) of seropositive neonatal calves (mean age 4.4 days). using a logistic binomial ... | 1996 | 8784491 |
| epizootiologic instability of bovine populations against babesia bovis (piroplasmida:babesiidae) in the region of poas, costa rica. | in poás (costa rica), more than 78% of the cattle population is susceptible to babesia bovis (babes, 1888) which indicates that care should be taken during animal movement to avoid tick exposure. seroprevalence is less than 22%; the frequency distribution of antibody titers is presented. significant differences (p < 0.05) were observed in the distribution of seropositive animals between ecological zones. lower mountain rain forest and lower mountain wet forest presented higher risk for seroposit ... | 1996 | 8784492 |
| comparative sensitivity of two tests for the diagnosis of multiple hemoparasite infection of cattle. | the purpose of this study was to evaluate the efficacy of light microscopy (lm) examination of blood smears and a multiplex polymerase chain reaction (mpcr) assay, in terms of their ability to detect cattle experimentally infected with babesia bovis, babesia bigemina, and anaplasma marginale. blood samples were collected from 32 intact, 1-2 year old, holstein bulls, previous to and after simultaneous inoculation of culture-derived or field isolates of b. bovis- and b. bigemina-infected erythrocy ... | 1996 | 8784493 |
| characterization of helper t cell responses against rhoptry-associated protein 1 (rap-1) of babesial parasites. | | 1996 | 8784494 |
| reactive oxygen and nitrogen intermediates and products from polyamine degradation are babesiacidal in vitro. | products released from activated macrophages have been demonstrated to have microbicidal activity against a variety of microorganisms. reactive oxygen intermediates (roi) and reactive nitrogen intermediates (rni) have been shown to affect the induction of degenerate (crisis) forms of plasmodium spp. polyamines are degraded into acrolein which has also been shown to be toxic to plasmodium spp. we have investigated the possibility that these products act similarly with babesia bovis. crisis forms ... | 1996 | 8784495 |
| use of polymerase chain reaction in bovine babesiosis research. | the polymerase chain reaction (pcr) in babesiosis research was originally developed to detect babesia bovis or babesia bigemina in blood samples containing infected erythrocytes. these preliminary studies led to development of a sensitive pcr/dna probe assay to detect the following hemoparasites: b. bigemina and b. bovis in a single sample. this modified procedure, referred to as a duplex pcr/ nonradioactive probe assay, has an analytic sensitivity of 0.00001% for b. bigemina, and 0.00001% infec ... | 1996 | 8784529 |
| light microscopy diagnosis of babesia bovis and b. bigemina kinetes in the hemolymph of artificially infected boophilus microplus engorged female ticks. | | 1996 | 8784530 |
| molecular cloning of a putative rhoptry associated protein homologue from babesia divergens. | | 1996 | 8784776 |
| piroplasms of domestic animals in the macedonia region of greece. 1. serological cross-reactions. | during a serological survey on haemoparasites in macedonia, serum samples were collected from cattle, sheep and goats. all sera were tested by the indirect immunofluorescence test (ifat); the cattle sera against theileria orientalis, t. annulata, babesia bigemina, b. bovis, b. divergens and b. major antigens; the sheep and goat sera against t. ovis, b. ovis, b. motasi and b. crassa antigens. parallel tests of negative and positive control sera against all the antigens showed the existence of cro ... | 1996 | 8792579 |
| piroplasms of domestic animals in the macedonia region of greece. 2. piroplasms of cattle. | a study was carried out on piroplasms of cattle in the macedonia region of greece. during 1984-1986, 602 serum samples were collected from cattle in 33 localities. blood smears were also prepared from 50 of the animals in 13 localities. the indirect fluorescent antibody (ifa) test revealed that 41.4% of cattle sera were positive to theileria orientalis, 2.0% to theileria annulata, 21.6% to babesia bovis, 15.2% to babesia bigemina, 5.1% to babesia major and 2.7% to babesia divergens. some of the ... | 1996 | 8792580 |
| effect of passage of babesia ovis in the gerbil (acomys cahirinus) on the course of infection in splenectomized lambs. | splenectomized gerbils (acomys cahirinus) have been found to be susceptible to babesia ovis applied via blood inoculation, whereas intact gerbils were not infected. blood from splenectomized latently infected gerbils caused infection in a splenectomized lamb. intact acomys cahirinus gerbils did not become infected by b. ovis, and all captured rodents in an enzootic area, intact and splenectomized, were found to be negative for b. ovis. it can thus be concluded that acomys cahirinus does not serv ... | 1996 | 8916410 |
| human interleukin-12 upregulates proliferation and interferon-gamma production by parasite antigen-stimulated th cell clones and gamma/delta t cells of cattle. | | 1996 | 8958944 |
| subunit vaccines for complex tick-borne pathogens: dream or reality? | | 1996 | 8979420 |
| prospects for subunit vaccines against tick-borne diseases. | tick-borne parasites are a serious impediment to the improvement of live-stock production in the developing world. the major parasites affecting cattle include theileria parva, t. annulata, babesia bigemina, b. bovis, anaplasma marginale and cowdria ruminantium. the control of these infections is dependent on the use of acaricides to decrease transmission by the tick vectors, and immunization of susceptible animals with live vaccines. the use of acaricide is hampered by the development of resist ... | 1996 | 8979421 |
| anaplasma marginale: detection of carrier cattle by pcr-elisa. | a highly sensitive and specific polymerase chain reaction (pcr) based assay for the detection of the minute levels of anaplasma marginale present in the blood of long-term carrier cattle was developed. a simple lysis method was used to remove most of the haemoglobin from the blood to facilitate direct input of samples into the pcr reactions without prior purification of the dna. pcr product was detected by enzyme-linked immunosorbent assay (elisa) to simplify the processing of large numbers of s ... | 1996 | 8982791 |
| the growing importance of the plastid-like dnas of the apicomplexa. | organisms in the phylum apicomplexa possess, in addition to their mitochondrial genome, an extrachromosomal dna that possesses significant similarities with the extrachromosomal genomes of plastids. to date, the majority of data on these plastid-like dnas have been obtained from the human malarial organism, plasmodium falciparum. in common with plastid dnas, the plastid-like dna of p. falciparum possesses genes for dna-dependent rna polymerase subunits beta and beta 1 and for organellar-like lar ... | 1996 | 9024859 |
| babesia bovis: biosynthesis and localisation of 12d3 antigen in bovine erythrocytes. | the 12d3 antigen of babesia bovis was found to be synthesised rapidly in cultured parasites, and localised to both the apical complex of the merozoite and the cytoplasm of the parasitised erythrocyte. amino-terminal sequencing suggested that the nascent protein had been processed and differences between the predicted and measured molecular weights suggested post-translational modification. the major proportion of 12d3 appeared in the soluble compartment of the parasitised erythrocytes with a mol ... | 1996 | 9024870 |
| comparison of the infectivity of babesia bovis, babesia bigemina and anaplasma centrale for cattle after cryopreservation in either dimethylsulphoxide (dmso) or polyvinylpyrrolidone (pvp). | | 1997 | 9034504 |
| effect of breed of cattle on innate resistance to infection with babesia bovis, b bigemina and anaplasma marginale. | to assess the innate resistance of naive bos taurus, bos taurus cross bos indicus and bos indicus cattle to virulent babesia bovis, b bigemina and anaplasma marginale parasites. | 1997 | 9196820 |
| immunisation of smallholder dairy cattle against anaplasmosis and babesiosis in malawi. | a field study was conducted in the southern region of malawi to evaluate the possible benefits of immunisation of improved dairy cattle against anaplasma marginale, babesia bigemina and babesia bovis. friesian crossbred heifers were immunised when they were being reared on government farms. they were then issued to smallholder farmers, together with unvaccinated controls, where many of them were exposed to heavy tick infestation. vaccination was shown to provide a significant degree of protectio ... | 1997 | 9203307 |
| an enzyme-linked immunosorbent assay (elisa) for the detection of antibodies against babesia bovis in cattle. | a method for the isolation of babesia bovis merozoites from infected erythrocytes (machado et al., 1994) and an enzyme-linked immunosorbent assay (elisa) for the detection of anti-b. bovis antibodies were developed. this elisa utilizes a soluble, alkali-digested b. bovis antigen. sera from calves experimentally infected with b. bovis were screened by this technique from day 9 to day 233 postinfection (pi). maximum titers were reached between days 29 and 149 pi. sera from calves (n = 62), heifers ... | 1997 | 9231985 |
| development of effective living vaccines against bovine babesiosis--the longest field trial? | between 1959 and 1996, research was performed to change a vaccine against babesiosis in australia and to improve it as actual or threatened untoward field responses became apparent. the most significant change occurred in 1964 with the traditionally used carriers of babesia being replaced as vaccine donors by acutely infected splenectomised calves. this ensured the infectivity of the vaccine and was fortuitously associated with a reduction in the virulence of babesia bovis in vaccine. since then ... | 1997 | 9279577 |
| genotypic diversity in field isolates of babesia bovis from cattle with babesiosis after vaccination. | to determine whether particular genotypes of babesia bovis were common to field isolates obtained from cattle properties in queensland where the b bovis vaccine had apparently failed. | 1997 | 9293339 |
| seasonal prevalence of ticks and tick-transmitted haemoparasites in traditionally managed n'dama cattle with reference to strategic tick control in the gambia. | a survey of tick spatial and seasonal distribution in traditional managed n'dama cattle over 1 year old was carried out in the gambia over 16 months. presence of anaplasma marginale and babesia spp. in the blood smears and their antibodies in the serum of same animals were also examined. tick species, in decreasing order of abundance, were: boophilus geigy, rhipicephalus senegalensis, b.decoloratus, hyalaomma truncatum, h.marginatum rufipes and amblyomma variegatum. all tick species peaked durin ... | 1997 | 9430113 |
| vaccination against babesia bovis: t cells from protected and unprotected animals show different cytokine profiles. | vaccination of cattle against the haemoprotozoan parasite, babesia bovis, with the recombinant antigen 11c5 resulted in 9 of 15 cattle being protected against challenge infection. the cellular immune responses of protected and unprotected cattle were compared in order to identify differences in response. no differences were observed in the pattern of change in various blood leukocyte populations throughout challenge infection. facscan analysis revealed an increase in the proportion of cells bear ... | 1997 | 9467739 |
| babesia bovis: genome size, number of chromosomes and telomeric probe hybridisation. | pulsed field gel electrophoresis of intact chromosomes of babesia bovis revealed four chromosomes in the haploid genome. a telomere probe, derived from plasmodium berghei, hybridised to eight sfii restriction fragments of genomic b. bovis dna digests indicating the presence of four chromosomes. a small subunit (18s) ribosomal rna gene probe hybridised to the third chromosome only. the genome size of b. bovis is estimated to be 9.4 million base pairs. the sizes of chromosomes 1, 2, 3 and 4 are es ... | 1997 | 9467743 |
| studies on the pathogenicity of babesia bovis in water buffaloes after cryopreservation and resuscitation. | packed erythrocytes infected with babesia bovis were mixed with an equal volume of 16% dimethyl sulphoxide (dmso) in alsever's solution and dispensed into 1.5 or 5 ml cryotubes. the vials were kept in liquid nitrogen (-196 degrees c) for 26, 78, 142 or 149 days. the samples were removed from the liquid nitrogen container and rapidly thawed in a 40 degrees c water bath. the thawed blood successfully infected splenectomised buffalo calves by injection via subcutaneous or intravenous or via intrave ... | 1997 | 9512744 |
| detection of babesia bovis using a dig-labeled dna probe. | a plasmid dna containing the inserted babesia bovis cdna clone designated c51a was used to prepare a dna probe for b. bovis. the purified 0.6 kb specific dna fragment was labeled by dig dna labeling. after denaturation, the probe was hybridised with the blotted target dna extracted from bovine red blood cells infected with b. bovis or other protozoa or bovine red blood cells plus extra white blood cells. it was found that the probe produced from purified 0.6 kb dna fragment could detect sample o ... | 1997 | 9512746 |
| helper t-cell epitopes encoded by the babesia bigemina rap-1 gene family in the constant and variant domains are conserved among parasite strains. | among important candidates for babesial vaccines are apical complex proteins, including rhoptry-associated protein 1 (rap-1) from babesia bovis and b. bigemina, which have been shown to induce partial immunity. four variant b. bigemina rap-1 transcripts identified in a clone of the mexico strain have highly conserved sequence in the central region but vary in sequence at the amino and carboxy termini (nt and ct) of the predicted proteins, resulting in different combinations of nt and ct domains ... | 1998 | 9529082 |
| comparison between enzyme-linked immunosorbent assay, indirect fluorescent antibody and rapid conglutination tests in detecting antibodies against babesia bovis. | the performance of an enzyme-linked immunosorbent assay (elisa), an indirect fluorescent antibody test (ifat) and a rapid conglutination test (rct) for the detection of antibodies against babesia bovis, was evaluated with 462 cattle sera from bahia state; brazil. the results showed a concordance of 96.6% between the elisa and ifat, 90.5% between the elisa and rct, and 91.8% between the ifat and rct. although the prevalence rates determined by elisa (97.2%) and ifat (96.8%) were higher than that ... | 1998 | 9561698 |
| relationships between vaccine and virulent strains of babesia bovis during co-infection in calves. | | 1998 | 9578770 |
| some quantitative aspects of natural babesial infection in the haemolymph of boophilus microplus engorged female ticks. | quantitative aspects of the natural babesial (babesia bovis and babesia bigemina) infection in boophilus microplus engorged female ticks obtained from two herds of holstein heifers positive by the immunofluorescent antibody test to both protozoan were evaluated. the number of kinetes/microscope field of haemolymph was determined for each tick from day 5 to 10 post-collection. a close relationship between daily and cumulative babesial infection was detected. correlation and determination coeffici ... | 1997 | 9587602 |
| the safety and efficacy of australian tick-borne disease vaccine strains in cattle in paraguay. | glycerol preserved, frozen tick-borne disease vaccine strains developed in australia were imported into paraguay to test their safety in pregnant holando heifers and their efficacy against challenge from inoculated local field strains of babesia bigemina, b. bovis and anaplasma marginale in hereford x criolla heifers. the two babesia strains proved to be safe and the b. bovis k strain was very effective in providing immunity to a local field strain of b. bovis. the b. bigemina efficacy trial was ... | 1998 | 9653988 |
| bovine babesiosis and anaplasmosis follow-up on cattle relocated in an endemic area for hemoparasitic diseases. | a multiplex pcr/dna probe assay was used to monitor babesia bovis, b. bigemina and anaplasma marginale infection in cattle introduced to a boophilus microplus-infested area in veracruz, mexico. eight intact, 18-month-old, cross-bred beef cattle (four naive, group a; four babesia species--premunized, group b) were immediately exposed to ticks after arrival and were clinically monitored from day 6 to day 98 post-exposure (pe) to ticks. blood sample analysis for dna detection by the mpcr/dna probe ... | 1998 | 9668444 |
| immunochemical methods for identification of babesia bovis antigens expressed on the erythrocyte surface. | intraerythrocytic parasites, such as babesia bovis, modify the erythrocyte plasma membrane structurally, antigenically, and functionally. for such parasites the infected erythrocyte surface also is thought to be a primary site for interaction with the host immune system. these properties demand characterization of the various alterations to understand the overall host-parasite interaction, immunity to disease or infection, and bases for parasite persistence. a paucity of adequate methods exists ... | 1997 | 9405201 |
| characterization of a variant erythrocyte surface antigen (vesa1) expressed by babesia bovis during antigenic variation. | babesia bovis, an intraerythrocytic, protozoal parasite of cattle, undergoes clonal antigenic variation (allred dr, cinque rm, lane tj, ahrens kp. infect immun 1994;62:91-98). this ability could provide a mechanism by which the parasite escapes host immune defenses to establish chronic infection. previous work identified two parasite-derived antigens of mr 128,000 and 113,000 that were present on the surface of the infected erythrocyte and appeared to be associated with clonal antigenic variatio ... | 1997 | 9364970 |
| evaluation of a frozen trivalent attenuated vaccine against babesiosis and anaplasmosis in brazil. | | 1998 | 9668502 |
| identification of babesia bovis antigens by monoclonal antibodies. | | 1998 | 9668505 |
| use of monoclonal antibodies for the identification of a common surface antigen of babesia bovis. | | 1998 | 9668506 |
| antigenic variation in babesia bovis: how similar is it to that in plasmodium falciparum? | despite significant differences in some aspects of their life-cycles, the apicomplexan parasites babesia bovis and plasmodium falciparum share many parallels. significant among these are participation in rapid, clonal antigenic variation, and cyto-adherence and sequestration in the deep vasculature. antigenic variation has long been thought to be primarily a mechanism of escape from antibody-mediated mechanisms of the host's immune system. in each species, the components demonstrated to particip ... | 1998 | 9683897 |
| immunodominant t-cell antigens and epitopes of babesia bovis and babesia bigemina. | despite convincing evidence that t cells are critical for both cellular and humoral immunity against haemoprotozoan parasites, the difficulty of performing meaningful experiments in cattle that would define the role of t cells in immunity to babesia spp. has impeded research in this area. however, experiments performed ex vivo with immune t cells can reflect in-vivo events, and provide valuable insight into the nature of immunogenic proteins and the responding lymphocytes. the progress made towa ... | 1998 | 9683898 |
| parasite localization and dissemination in the babesia-infected host. | babesia bovis infections in cattle and b. canis infections in dogs are characterized by non-haemolytic anaemia and low parasitaemia during the acute phase of the disease. in this phase of the disease, animals suffer from hypotension followed by disturbances of the coagulation system. this review discusses the hypothesis that may explain the process of parasite localization in the host, and the consequences of such localization. it is suggested that hypotension favours the interaction between inf ... | 1998 | 9683902 |
| [investigation of babesia in farm workers and blood donors in the province of ciego de avila]. | a descriptive study of cases was conducted in which 781 sera were investigated using the indirect immunofluorescent technique with antigens of babesia bovis and babesia bigemina at the national center for agricultural health. of them, 371 came from agricultural workers and 410 from donors in the province of ciego de avila. it was started from dilutions of 1/64. an epidemiological survey was done to each seropositive so as to know the risk factors. the test of difference of proportions was used t ... | 1997 | 9685976 |
| stimulation of nitric oxide production in macrophages by babesia bovis. | gamma interferon (ifn-gamma)-activated macrophages are believed to play a key role in resistance to babesia bovis through parasite suppression by macrophage secretory products. however, relatively little is known about interactions between this intraerythrocytic parasite and the macrophages of its bovine host. in this study, we examined the in vitro effect of intact and fractionated b. bovis merozoites on bovine macrophage nitric oxide (no) production. in the presence of ifn-gamma, b. bovis mero ... | 1998 | 9712758 |
| bovine babesiosis in dual purpose calves in the state of yucatan, mexico. | thirty-eight dual purpose calves in the 3 agricultural zones of the state of yucatan, mexico were monitored for antibodies to babesia bovis and b. bigemina from close to birth up to 12 months of age. the results showed that infection with both parasites is widespread throughout the 3 zones. many of the animals had produced antibody to both parasites by 6 months of age indicating high transmission rates resulting in enzootic stability for both parasites. any changes to agricultural practices in t ... | 1998 | 9719829 |
| babesia bovis: identification of immunodominant merozoite surface proteins in soluble culture-derived exoantigen. | babesia bovis merozoite proteins presenting as exoantigens in in vitro culture supernatants have been characterized. bovine antisera to b. bovis exoantigens were used to immunoprecipitate [35s]-methionine metabolically labeled or lactoperoxidase-catalyzed radioiodinated b. bovis merozoite proteins. a total of 24 metabolically labeled proteins ranging in molecular weight from 24,000 to 225,000 da and 9 radioiodinated proteins with molecular weights varying between 24,000 and 225,000 da were ident ... | 1997 | 9342742 |
| sequence and functional analysis of the intergenic regions separating babesial rhoptry-associated protein-1 (rap-1) genes. | the rhoptry-associated protein 1 (rap-1) expressed by all babesial parasites is encoded by tandemly arranged genes separated by discrete intergenic (ig) regions. we hypothesize that these ig regions regulate rap-1 gene expression. in babesia bovis two identical rap-1 gene copies are separated by a 1.0-kb noncoding region which is also exactly conserved 5' to the rap-1 gene 1. in contrast, the complex b. bigemina rap-1 locus contains at least 5 polymorphic rap-1a genes separated by uncharacterize ... | 1998 | 9769249 |
| dna and a cpg oligonucleotide derived from babesia bovis are mitogenic for bovine b cells. | dnas from bacteria and variety of nonvertebrate organisms, including nematodes, mollusks, yeasts, and insects, cause polyclonal activation of murine b lymphocytes. similar studies have not been reported for bovine b cells, and to date no studies have reported mitogenic properties of protozoal dna for any species. however, we and others have observed that protozoal parasite antigens can induce the proliferation of lymphocytes from nonexposed donors. extending these studies, we now show that the m ... | 1998 | 9784553 |
| the absence of clinical disease in cattle in communal grazing areas where farmers are changing from an intensive dipping programme to one of endemic stability to tick-borne diseases. | a two-year field study was conducted in four communal grazing areas in south africa. sera were collected from young cattle (6-18 months old) in these areas during the winters of 1991 to 1993. the sera were tested for antibodies to babesia bovis, babesia bigemina, anaplasma marginale and cowdria ruminantium. in two of the four areas, treatment with acaricide was erratic and dependent on the discretion of individual owners. in these areas the drought of 1992 had a major impact on tick burdens and ... | 1998 | 9809321 |
| seroprevalence of babesia ovis in sheep in catalonia, northeastern spain. | an indirect fluorescent antibody test (ifat) was developed in order to detect antibodies against babesia ovis in different sheep flocks from catalonia, northeastern spain. of the total 2174 sera included in the study, 133 (6.1%) were positive. considerable differences in seroprevalence were detected depending on the geographical areas from which the animals originated. this must have been a consequence of the presence or absence of the vector tick, rhipicephalus bursa, the distribution of which ... | 1998 | 9831951 |
| seroprevalence of babesia ovis in goats in catalonia, spain. | | 1998 | 9839368 |
| babesia bovis: common protein fractions recognized by oligoclonal b. bovis-specific cd4+ t cell lines from genetically diverse cattle. | cd4+ helper t cells are believed to be important for inducing protective immunity against babesia bovis through the production of cytokines, including ifn-gamma, that will provide help to b lymphocytes for igg production and activate macrophages to become parasiticidal. to provide maximum protection in an outbred population, an effective vaccine against b. bovis should contain antigens that would elicit an ifn-gamma response and would be recognized by cattle with diverse genetic backgrounds. to ... | 1999 | 9920041 |
| upregulation of interleukin-4 and ifn-gamma expression by ifn-tau, a member of the type i ifn family. | trophoblast interferon-tau (ifn-tau) is a new member of the type i ifn family that is produced in large quantities by the ruminant conceptus. like other type i ifn, ifn-tau inhibits viral replication and activates natural killer (nk)-mediated cytotoxicity. in mice and humans, type i ifn enhances type 1 t helper (th) cell responses, but the effects of type i ifn, including ifn-tau, on cytokine expression by bovine th cells have not been described. the present study determined the effects of ifn-t ... | 1999 | 10090403 |
| epidemiology of tick-borne diseases of cattle in botshabelo and thaba nchu in the free state province. | a seroepidemiological study was conducted on 151 cattle from the botshabelo and thaba nchu areas in the central free state province of south africa, two areas where small scale, peri-urban cattle farming is practised. an indirect fluorescent antibody test was used to test for babesia bigemina and b. bovis antibodies. to test for anaplasma marginale antibodies a competitive inhibition enzyme-linked immunosorbent assay method was used. there were no significant differences in serological test resu ... | 1998 | 10192841 |
| vaccines against bovine babesiosis--longest field trial? | | 1999 | 10197254 |
| pcr methods for the discrimination of babesia bovis isolates. | three different polymerase chain reaction assays for the typing of isolates of babesia bovis have been developed and compared with a hybridisation based method. primers were designed within conserved regions flanking the variable length tandem repeats of the bv80 and bvva1 genes. for the long array of repeats in bvva1, up to 7.5 kb, a modified long template pcr method was developed. the assays were compared using ten independent isolates of babesia bovis. using the bvva1 and bv80 pcr assays, 13 ... | 1997 | 9299692 |
| cross-sectional estimation of babesia bovis antibody prevalence in an area of argentina used for extensive cattle breeding as an aid to control babesiosis. | the prevalence of babesia bovis antibodies was estimated by using an elisa (98% sensitivity and 95% specificity). sera were obtained from 165 calves (mean age and standard deviation: 9.7 +/- 2.7 months) from an area in argentina known to be unfavourable for the development of the vector tick, boophilus microplus. the area comprised about 300,000 ha used for cattle breeding. the cattle population of 55,000 included 12,000 cattle under 1 year of age. cattle were maintained mainly on natural grasse ... | 1997 | 9234418 |
| babesial antibody dynamics after cattle immunisation with live vaccines, measured with an indirect immunofluorescence test. | the efficacy of vaccination of argentinean cattle against babesiosis and anaplasmosis using live immunogens was tested to detect specific antibodies in samples obtained about 60 days after vaccination. under these conditions a higher than expected proportion of cattle failed to show antibodies against babesia bigemina. therefore, a study was designed to evaluate if this failure was due to insensitivity of the routine test to detect antibodies to b. bigemina or to lack of infectivity of the live ... | 1997 | 9195707 |